Electrical enclosures typically include an outer housing and a door and are manufactured of a plastic or a metal, such as steel. The outer housing and door form an enclosure which houses electrical components, such as switches. The door is typically made of sheet metal having sufficient strength to avoid unwanted contamination of the electrical components by dust or water. These doors lack rigidity, and, especially with larger doors, may be perceived to be flimsy and thus cheap by some customers. Moreover, it has become desirable to mount electrical accessories to the inner side of the door. Sheet metal doors generally lack the rigidity and mounting surface necessary to durably and easily accommodate such accessories.
To increase the rigidity of electrical enclosure doors and to facilitate mounting of accessories, door-support frame assemblies, such as the assembly disclosed in German Patent No. 41 03 785 C2 to Reuter, have been used. These frame assemblies typically include a pair of vertical tubular members, a pair of horizontal tubular members and four corner fasteners, which interconnect the vertical tubes with the horizontal tubes to form a generally rectangular frame assembly. The frame assembly is mounted to the inner side of the door using a number of threaded nut and bolt assemblies. To facilitate the mounting of accessories, the frame assembly is provided with bore holes along its tubes for mounting accessories on the frame assembly
Typically, a number of threaded bolts are mounted to the inner side of the door and are received by holes in the frame assembly. The holes also receive internally threaded nuts, which are provided with guide sleeves onto which a washer is placed. The guide sleeves then receive the threaded bolts so that the nuts can be screwed to the bolts to mount the frame assembly to the door. Typically, a threaded nut and bolt assembly is used in each corner of the frame assembly and in the middle of the vertical tubes if the cabinet is tall. However, in these frame assemblies, the threaded nuts protrude from an outer plane of the frame assembly. The protruding nuts limit the ability to mount accessories and also catch on objects, such as a user's clothes.
Consequently, there is a need in the electrical enclosure industry for a door-support frame assembly which increases the rigidity of the door and provides an unobstructed surface for mounting accessories. The present invention addresses this and other needs associated with frame assemblies.